Process for the manufacture of a profile part

ABSTRACT

A compound profile (43) consists of a fastening section (33) of a thermoplastic plastics material as well as profile sections (30, 31) of elastomeric material, namely a profile section (30) of expanded rubber and a profile section (31) of soft rubber. All sections (30, 31, 33) are fixed to one another by co-extrusion and co-vulcanization. The plastics material fastening section (33) assumes the function of the conventional metallic reinforcement of the compound profile (43). The compound profile (43) can be three-dimensionally shaped in that it is heated up to the plasticization temperature of the fastening section (33), then is brought to the desired shape in a shaping tool, and in that shape is cooled until the fastening section (33) has again returned to its non-plastic state. One thus creates a profile part which is stable in shape.

BACKGROUND

The invention relates to a process for the manufacture of a profile partin which at least one profile section of an elastomeric material isconnected to at least one fastening section and the compound profilethus created is made into the desired shape.

In one known process of this type (Patent Abstracts of Japan, Vol. 17,No. 368 (M-1443) an extruder 27 feeds thermoplastic plastics material 29directly into a multi-component extrusion head 25. In the extrusion headthis plastics material forms a base member which, together with asealing member of flexible rubber, is co-extruded from the extrusionhead. The combined profile 33 travels into a vulcanizing tank 31 inwhich the sealing member is vulcanized.

In the known so-called "stretch bending" process, the fastening sectionconsists of a metallic reinforcement. The finished compound profile ishere bent into the particular shape in which it is finally to be used asa profile part on a motor vehicle using special tools and in a mannerwhich is costly to carry out. Because of the constructional tolerances,during the fitting, one regularly has to carry out costly adjustments tothe compound profile which has been stretched and bent.

From Patent Abstracts of Japan, Vol. 5, No. 158 (M-091), it is known perse initially to extrude a tube 2 of polyamide from an extruder 1. Thetube is subsequently cooled and passed through a braiding machine 4which applies a reinforcing layer 5 of brass-plated or zinc-plated wire.A subsequent extruder 6 generates an outer coating 7 of rubber which isvulcanized in a vulcanizing installation 8 and is connected to the wirereinforcement layer 5.

From EP 528 560 A1 it is known per se to supply thermoplastic plasticsmaterial 19, 21 and unvulcanized rubber 13, 15 to a multi-componentextrusion head 17. The result is a combination profile 10a whose baseportion 1 is of rubber. individual surface strips of the base portionare overlaid with thin anti-friction layers 11 of the thermoplasticplastics material.

From EP 483 758 A1 it is known per se to co-extrude a profile 11 havinga base portion 12 of rubber and a sealing portion 13 of sponge rubberwhich has a drainage lip 14. The base portion is fixed by fasteningmembers 4 which extend through mounting holes in a vehicle body panel.

From Patent Abstracts of Japan, Vol. 17, No. 483 (M-1472) it is knownper se to lock a sealing lip 4 of a profile to a base member 2 by meansof a connecting part 9. In order to assemble the profile the sealing lip4 is pivoted away so that the base portion 2 can be fixed by screws 10to the bodywork. Subsequently, the sealing lip 4 is pivoted back,whereupon the coupling members 17, 20 engage in each other.

From DE 37 891 A1 the co-vulcanization of thermoplastic plasticsmaterials and elastomeric materials is known per se. Mention is made ofa process involving a two-stage extrusion method, which is expensive interms of time and production.

From DE 42 19 344 A1 it is known per se to manufacture a part 1 in ashaping tool 4 to 7 by a sandwich injection molding where the part has acore 3 of a resin mixture, chiefly of PP (page 5, lines 50 and 51), anda skin layer 2 of a resin (page 5, line 55), namely a thermoplasticelastomeric material based on styrene, which mainly consists of SEBS(page 5, lines 49 and 50).

From DE 39 34 091 A1 it is known per se to create compound bodies in twosteps, the compound bodies consisting of a thermoplastic materialreinforced by endless fibers and of rubber, and which can be fixedlyconnected to each other by vulcanization without the use of adhesivemeans, primers or glue. As a rule, in the first step, the thermoplasticmaterial is bonded to a fibrous strengthening support, for example aweb, UD tape and the like.

From DE 38 35 211 A1 it is known per se to extrude from a commonextrusion head 21 a sealing strip 1 consisting of a U-shaped clampingstrip 4 of hard rubber, a complete sleeve 5 completely around theclamping strip 4 and having lips 9, 10 of soft rubber and a sealing tube3 of expanded rubber. The compound profile 1 subsequently passes througha heating station 22 and a hot air zone 23 which completes thevulcanization.

From DE-OS 2 330 605 it is known per se to heat a thermoplasticpolyamide synthetic resin material so that at least its surface issoftened, and then to bring this surface into contact with a rubbercompound, whereafter the softened surface in contact with the rubbercompound is allowed to cool off. By this means the rubber compound canbe vulcanized.

From the German book "Einstieg in die Kunststoffchemie", 3rd edition, byB. Gnauck and P. Frundt, published by Carl Hanser Verlag, Munich/Vienna,1991, page 31, it is known per se to thermoform thermoplastic plasticsmaterials. Thermoplastics are formable plastically by the supply ofsufficient heat and after cooling off to normal temperatures they becomerigid again and can be subjected to loads.

SUMMARY OF THE INVENTION

It is an object of the present invention to improve and to simplify theproduction and the fitting of profile parts.

This object is achieved by the features of a process as described hereinfor producing a compound profile part having plasticizable constituents.The part has at least one profile section of elastomeric material, andat least one fastening section of thermoplastic plastics material.

The thermoplastic plastics material is extruded, calibrated and cooledto a temperature compatible for co-extrusion with the elastomericmaterial. The fastening section and profile section are thenco-extruded. The two sections are chemically bonded to each other byco-vulcanization. A desired length of the co-extruded piece is thenheated where necessary, depending on the desired shape, until itsplasticizable constituents are in the plastic state. The length is thenshaped into the desired shape and cooled to the non-plastic state whilemaintaining the desired shape. Profile parts in accordance with theinvention are of particular interest for use in vehicles, in which theoriginal profile has to be deformed three-dimensionally to make profileparts. It is a permanent aim of the vehicle designed to reduce the c_(w)value and the construction cost of the motor vehicle. The result is thatthe bodywork is always more strongly rounded and ornamentation and sealswhich are fitted externally to the bodywork must follow this shaping.For this it is necessary to deform compound profiles in all threecoordinates. The process according to the present invention makes itpossible to completely eliminate metal as a material for the at leastone fastening section. The compound profiles manufactured according tothe invention are cut to length and just by heating, shaping in ashaping tool and cooling in the thus formed shape are made into profileparts having extraordinarily high fitting accuracy. The fitting of theprofile parts manufactured in this way is considerably facilitated,since the profile parts already have the optimum snug fit for thereceiving track on the bodywork. A further advantage in addition to theimproved fitting is that such optimized prefabricated profile partsensure that the sealing effect when fitted is also optimized when one istalking about sealing profiles. Profile parts manufactured in accordancewith the invention can, however, also be used for example as rainwaterducts. In all profile parts made in accordance with the invention thefastening section can be designed to be of thermoplastic plasticsmaterial and its cross-section can be shaped such that the necessarystrength and shape stability results for the whole profile part later.The shape of the profile part achieved after the cooling by the factthat the fastening section is no longer in the plastic state isso-to-speak "frozen in" and does not change any more up to theinstallation of the profile part. The manufacture of the compoundprofile by co-extrusion and co-vulcanization gives advantages in termsof technical manufacture.

The extrusion of the fastening section can be effected at temperaturesgreater than 220° C. In advance of the multi-component injection headthe cooling and a calibration of the shaped fastening section to aco-extrusion temperature is effected. Thermoplastic elastomericmaterials (TPE) are co-extruded together with the fastening section attemperatures of 150° to 190° C., are cooled to room temperature andcalibrated. For the elastomeric materials the extrusion generally takesplace at 80° to 120° C., with the temperature input sufficient for thecross-linking in the vulcanization stage, for example in the salt bathor in a fluid bed. Thus, the fastening section and the profile sectionare each prepared in the compound profile so that they are optimized fortheir later tasks.

With the use of a coupling material providing the chemical bond, thedesired fixed bonding between components can still be achieved by thismeans.

Particular features of profile parts and additional embodimentsmanufactured in accordance with the invention are set out herein by wayof example.

Further features and advantages of the invention will become apparentfrom the following description of a number of preferred embodiments inaccordance with the invention which are given by way of example and withreference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a compound profile before the shaping;

FIG. 2 shows three interactive profile parts produced from the compoundprofile of FIG. 1;

FIG. 3 is the cross-sectional view taken along the line III--III in FIG.1, on an enlarged scale;

FIG. 4 is a cross-sectional view through another fitted profile part;

FIG. 5 is a cross-section through a further fitted profile part; and

FIG. 6 is a cross-section through yet another profile part.

DESCRIPTION OF PREFERRED EMBODIMENTS

There is shown in FIG. 1 a compound profile 43 which has been producedas a continuous element by co-extrusion and co-vulcanization of severalsections. In FIG. 3 only one profile section 30 of expanded rubber is tobe seen overlying large peripheral regions of the compound profile 43.The remaining sections will be described in detail in connection withFIG. 3.

In the further processing, pieces of suitable length are cut from thecompound profile 43 and are heated in a shaping tool (not shown),possibly only locally, until thermoplastic sections of the compoundprofile 43 are transformed into the plastic state. Then, the compoundprofile piece is brought to the desired shape in the shaping tool, andsubsequently is cooled until the plasticized sections of the compoundprofile 43 have again returned to their non-plastic state. One therebyachieves profile parts 1, 2 and 3 as shown in FIG. 2, which are used forexample as sealing profiles in the roof cover of a cabriolet vehicle.The end faces of the profile parts 1 to 3 can be closed off, asnecessary, in a manner known per se, by caps or other ready-madeclosures, and in the extended condition of the roof cover will lie insealing contact with one another along boundary lines 4 and 5. In orderto simplify the drawing, the other parts of the cabriolet roof coverhave been omitted in FIG. 2.

In practical terms, the invention is suitable not just for the creationof two-dimensional or three-dimensional shaped sealing profiles for theroof frame of folding roof covers or for hard tops. In particular, theinvention makes it possible to manufacture in this way for the motorvehicle industry seals which are an accurate fit and stable in shape asrainwater drip channels, water and fresh air chamber seals under thebonnet or hood of motor vehicles, drop glass channel profiles andcantrail seals for saloon cars. In all cases, at least one fasteningsection 33 and 55 of a thermoplastic plastics material assumes thefunction of the previous metallic fixing rail.

The heating of the compound profile in order to achieve the plasticstate of its plasticizable constituents can be effected for example by aheating radiator, hot air blower or high frequency radiation.

In all the Figures of the drawings the same parts are indicated by therespective same reference numerals.

FIG. 3 shows a compound profile 43 in which the profile section 30 is ofexpanded rubber and almost completely encloses the fastening section 33.In the interior of the profile section 30 there is arranged a profilesection 31 which likewise consists of an elastomer, in this case of softrubber, and it has a chemical bond with the profile section 30 at theboundary surfaces. Between the profile sections 30 and 31 arethroughgoing hollow chambers 44 and 45 to improve the elasticityproperties of the compound profile 43.

The fastening section 33 in FIG. 3 has a substantially T-shapedcross-section and is partially embedded in the profile sections 30, 31.Here again, at the boundary surfaces, a sufficiently strong chemicalbond is created on the basis of the aforesaid co-extrusion andco-vulcanization.

At its lower free end the compound profile 43 shown in FIG. 3 hasmounting holes 46 which are arranged spaced from one another in thelongitudinal direction. Through these mounting holes 46 are insertedrespective fastening elements which can be connected to a part of thebodywork (not shown). A lip 48 of the profile section 30 which is madeof expanded rubber overlies the mounting holes 46. The compound profile43 serves for example as a sealing profile for the upper transversesection of the roof frame of a folding cover or hard top for a cabrioletor for a coupe type vehicle.

FIG. 4 shows another compound profile 29 which is composed of fourprofile sections 30 to 33. The profile sections 30 and 32 are ofexpanded rubber, with the profile section 30 having a through-goinghollow chamber 34 provided therein, in order to improve its springproperties.

The profile section 31 is likewise provided with a through-going hollowchamber 35 in order to achieve optimum spring properties. The profilesection 31 consists of an elastomer, like the profile sections 30 and32.

As elastomers for the profile sections, for example 30 to 32, thefollowing materials for example can be used in all the Figures:

expanded rubber with a Shore-A hardness of 10 to 30 or soft rubber witha Shore-A hardness of 30 to 70,

both manufactured for example from

EPDM,

SBR,

CR,

ECO,

blends (mixtures) of EPDM with SBR with an EPDM content of 20 to 90% byweight,

blends of EPDM with SBR and/or polyoctenamer, or NBR.

The following thermoplastic elastomeric materials (TPE) can also be usedby way of example:

TPE based on styrene ethylene butylene styrene (S-EB-S),

TPE based on styrene butadiene styrene (SBS),

TPE based on styrene isoprene styrene (SIS),

TPE based on elastomeric compositions as TPO blends or TPO alloys, forexample of cross-linked EPDM/propylene blends (EPDM/PP) or

ethylene vinyl acetate/vinylidene chloride (EVA/PVDC) or TPE based onthermoplastic polyurethanes (TPU).

The profile sections, for example 30 to 32, are each formed by anelastomer extruder and subsequently are vulcanized to one another alongthe boundary surfaces which are in contact with each other. Thus, achemical bond of sufficient strength is created between the respectiveprofile section.

The fastening section 33 consists in contrast of a thermoplasticplastics material in all Figures. The following materials can be usedfor this, example:

PPE polyphenylene ether

PP polypropylene

PE (LDPE, low density PE)

PE (HDPE, high density PE)

PIB polyisobutylene

PS polystyrene

PA polyamide

PC polycarbonate

PETP polyethylene terephthalate

POM polyoxymethylene,

epoxy resin

phenol formaldehyde resin

PES polyester

PPO polyphenylether or

PVC polyvinylchloride.

These plastics materials can be used with or without reinforcement, forexample by carbon fibers or glass fibers.

The fastening section 33 is produced by a plastics material extruderwith subsequent calibrating and cooling regions, and is co-extruded withthe profile sections 30 to 32 in a multi-component extrusion head. Bymeans of the subsequent co-vulcanization a sufficiently strong chemicalbond is created between the profile sections 31 and 33.

The compound profile 29 which is thus created as shown in FIG. 4 is heldon the one hand by an anchor groove 36 at a folded edge 37 of a motorvehicle bodywork panel 38, and on the other hand by a metal-cuttingscrew 39 which penetrates through the profile section 33 and into abodywork panel 40. Thus, with the simplest means, one achieves a stableconnection of the compound profile 29 to the bodywork 38. The compoundprofile 29 serves for example as a sealing profile for the side parts ofthe roof frame of a folding top or hard top for a cabriolet or a coupetype vehicle.

FIG. 5 shows a compound profile which is structured and formedsubstantially in the same way as the compound profile 29 shown in FIG.4. Again, the connection to the motor vehicle bodywork 38 isaccomplished in the same way as in FIG. 4. The difference as comparedwith FIG. 4 lies in the fact that between the profile sections 31 and 33there is now provided a layer of a coupling material 42. The purpose ofthe coupling material 42 is to improve the chemical bond between theelastomeric material of the profile section 31 and the thermoplasticplastics material of the fastening profile 33. The following materialscan be used for example as the coupling material 42:

EPDM in a blend with PP, PE, PS, PIB, PES, as well as other polymersfrom the aforesaid listing of the materials for the fastening profile33, in a proportion by weight of<20%,

blends of EPDM-CR-SBR-polyoctenamer or EPDM compounds with resinadditions (for example epoxy resins).

If the profile section 32 is of a TPE, then a polypropylene primer canbe used for example as coupling material 42.

FIG. 6 shows yet another compound profile 47 which is particularlysuitable as a sealing profile for the front transverse section and theside parts of the roof frame of a folding cover or hard top for acabriolet or for a coupe type vehicle.

The compound profile 47 comprises a fastening section 33 of athermoplastic plastics material which has a substantially U-shapedcross-section. The fastening section 33 is provided with a plurality ofmounting holes 46 which are arranged spaced from one another in thelongitudinal direction. These mounting holes each have all-round playwith reference to metal-cutting screws 39. Thus, the compound profile 47can be displaced relative to the screws 39 within limits in thelongitudinal and transverse directions during the fitting, until theoptimum position for the compound profile 47 has been achieved. Then thescrews are tightened in place.

One longitudinal end of the fastening section 33 is formed as a firstcoupling member 49. A masking profile section 50 is vulcanized onto thefastening section 33 on its lengthwise side which lies opposite to thefirst coupling member 49. The masking profile section 50 includes anadditional profile section 51 of expanded rubber which is vulcanizedonto a base 52 and onto a leg 53 of the fastening section 33 by means ofthe coupling material 42. A constituent part of the masking profilesection 50 is a further profile section 54 of soft rubber which overliesthe fastening section 33 and which has one longitudinal end vulcanizedto the additional profile section 51 and has its other longitudinal endvulcanized to a coupling profile section 55. The coupling profilesection 55 consists of a thermoplastic plastics material and comprises asecond coupling member 57 which forms a snap closure 56 with the firstcoupling member 49.

A sealing profile section 58 of expanded rubber is vulcanized by meansof the coupling material 42 to the side of the fastening section 33which lies opposite the additional profile section 51.

In FIG. 6 there is indicated in chain-dotted lines, at the top, thebodywork panel 40 to which the compound profile 47 is to be fitted. Thetoothed parts of the profile sections 51, 58 are pressed sealinglyagainst the bodywork panel 40 and are correspondingly deformed. Untilthe aforementioned fitting of the metal-cutting screws 39, the snapclosure 56 is free and the further profile section 54 hangs downwardsout of the way of the screwdriver. After the fitting of the screws 39the further profile section 54 with the coupling profile section 55 isfolded upwards and the snap closure 56 is closed. This creates a hollowchamber 59 into which, due to a window 60 of the motor vehicle, thefurther profile section 54 can be deformed upon putting the roofcovering in place, as is indicated by chain-dotted lines in FIG. 6.

In FIG. 6 the major part of the external surface of the additionalprofile section 51 and of the further profile section B4 are overlaidwith a sliding layer 61 which is indicated as being comparatively thickbut which in practice is just a thin coating. The sliding layer 61reduces the sliding friction between the further section 54 and thewindow 60.

While presently preferred embodiments of the invention have beendescribed with reference to FIGS. 2-6, it will be apparent that manymodifications and variations may be effected without departing from thescope of the novel concepts of the present invention.

What is claimed is:
 1. A process for producing a compound profile parthaving plasticizable constituents, said profile part having at least oneprofile section made of an elastomeric material and at least onefastening section made of a thermoplastic plastics material; saidprocess comprising the steps of:(a) extruding said thermoplasticplastics material; (b) subsequently calibrating said thermoplasticplastics material extruded in step (a), and cooling said thermoplasticplastics material extruded in step (a) to a temperature compatible forco-extrusion with said elastomeric materials; (c) co-extrudingcontinuous lengths of said thermoplastic plastics material calibratedand cooled in step (b) and said elastomeric material for forming thecompound profile; (d) chemically bonding said thermoplastic plasticsmaterial and said elastomeric material to each other by covulcanization;(e) cutting said continuous co-extruded lengths to a length; (f) heatingsaid length where necessary depending upon the location of a desiredchange in shape until its plasticizable constituents are in a plasticstate; (g) shaping said length after step (f) in a shaping tool into thedesired shape; and (h) cooling said length to a non-plastic state of theplasticizable constituents while maintaining the desired shape of step(g).
 2. A process according to claim 1 comprising the further step ofusing a coupling material in the co-extrusion step to promote thechemical bond between said thermoplastic plastics material and saidelastomeric material.
 3. A profile part made by the process according toclaim 1 whereinsaid fastening section of thermoplastic plastics materialis adopted to be fastenable to a bodywork panel; and said profilesection comprises a first profile section made of soft rubber vulcanizedto said fastening section.
 4. A profile part made by the processaccording to claim 2 whereinsaid fastening section of thermoplasticplastics material is adapted to be fastenable to a bodywork panel; andsaid profile section comprises a first profile section made of softrubber vulcanized to said fastening section.
 5. A profile part inaccordance with claim 3 further comprising at least one additionalprofile section of expanded rubber vulcanized to said first profilesection, said additional profile section being arranged to be coupled tothe bodywork panel.
 6. A profile part in accordance with claim 4 furthercomprising at least one additional profile section of expanded rubbervulcanized to said first profile section, said additional profilesection being arranged to be coupled to the bodywork panel.
 7. A profilepart made by the process according to claim 1 whereinsaid fasteningsection of thermoplastic plastics material is substantially T-shaped;said profile section comprises a first profile section made of softrubber vulcanized to a first portion of a periphery of said fasteningsection; and said profile part further comprises an additional profilesection of expanded rubber vulcanized to a second portion of theperiphery of said fastening section and to said first profile section.8. A profile part made by the process according to claim 2 whereinsaidfastening section of thermoplastic plastics material is substantiallyT-shaped; said profile section comprises a first profile section made ofsoft rubber vulcanized to a first portion of a periphery of saidfastening section; and said profile part further comprises an additionalprofile section of expanded rubber vulcanized to a second portion of theperiphery of said fastening section and to said first profile section.9. A profile part in accordance with claim 7 wherein said additionalprofile section encloses substantially the whole remaining compoundprofile, and along one longitudinal edge thereof extends a lip abovemounting holes for the receipt of fastening elements, wherein themounting holes are located in the fastening section and anotherlongitudinal edge of said additional profile section.
 10. A profile partin accordance with claim 8 wherein said additional profile sectionencloses substantially the whole remaining compound profile, and alongone longitudinal edge thereof extends a lip above mounting holes for thereceipt of fastening elements, wherein the mounting holes are located inthe fastening section and another longitudinal edge of said additionalprofile section.
 11. A profile part made by the process according toclaim 1 whereinsaid fastening section of thermoplastic plastics materialis substantially U-shaped and has a base that has mounting holes forreceiving fastening elements; said fastening section includes alongitudinal end forming a first coupling member; and said profile partfurther comprises a masking profile section vulcanized to said fasteningsection on a longitudinal side of said fastening section which liesopposite said first coupling member, and wherein said masking profilesection has a free longitudinal edge provided with a second couplingmember which forms a snap closure with the first coupling member.
 12. Aprofile part made by the process according to claim 2 whereinsaidfastening section of thermoplastic plastics material is substantiallyU-shaped and has a base that has mounting holes for receiving fasteningelements; said fastening section includes a longitudinal end forming afirst coupling member; and said profile part further comprises a maskingprofile section vulcanized to said fastening section on a longitudinalside of said fastening section which lies opposite said first couplingmember, and wherein said masking profile section has a free longitudinaledge provided with a second coupling member which forms a snap closurewith the first coupling member.
 13. A profile part in accordance withclaim 11 wherein said masking profile section includes a further profilesection of soft rubber which can overlie the fastening section.
 14. Aprofile part in accordance with claim 12 wherein said masking profilesection includes a further profile section of soft rubber which canoverlie the fastening section.
 15. A profile part in accordance withclaim 13 wherein said further profile section includes a longitudinaledge which is vulcanized to an additional profile section of expandedrubber, said additional profile section being vulcanized to thefastening section.
 16. A profile part in accordance with claim 14wherein said further profile section includes a longitudinal edge whichis vulcanized to an additional profile section of expanded rubber, saidadditional profile section being vulcanized to the fastening section.17. A profile part in accordance with claim 11 wherein said secondcoupling member is formed as part of a coupling profile sectioncomprising thermoplastic plastics material, and said coupling profilesection is vulcanized to the masking profile section which compriseselastomeric material.
 18. A profile part in accordance with claim 12wherein said second coupling member is formed as part of a couplingprofile section comprising thermoplastic plastics material, and saidcoupling profile section is vulcanized to the masking profile sectionwhich comprises elastomeric material.
 19. A profile part in accordancewith claim 13 wherein said second coupling member is formed as part of acoupling profile section comprising thermoplastic plastics material, andsaid coupling profile section is vulcanized to the masking profilesection which comprises elastomeric material.
 20. A profile part inaccordance with claim 15 wherein said second coupling member is formedas part of a coupling profile section comprising thermoplastic plasticsmaterial, and said coupling profile section is vulcanized to the maskingprofile section which comprises elastomeric material.
 21. The processfor producing the compound profile of claim 2 wherein the extrusion ofthe thermoplastic plastics material of step (a) is effected at atemperature greater than about 220° C., and the co-extrusion in step (c)is effected at a temperature below about 190° C.